Sub-module photovoltaic control system

Abstract

A method and apparatus for operating a photovoltaic cell array provide for collecting power generated by each group of at least one but less than all of the cells of the array using each of a plurality of controllers, one controller for each group; converting the collected power at each controller to have a common output parameter, the common output parameter value being greater than the value of the same parameter at each of the individual cells; and combining the outputs from the controllers to generate an output for the array. Each controller thus has connected to it a group of one or more, but less than all, of the photovoltaic cells of the array, and the outputs of the controllers are connected preferably in parallel but potentially in series as well. The cells connected to the controllers are also connected in series, parallel, or a combination of the two. In this manner, the array output can be at or near its optimum power with each group of photovoltaic cells operating near their peak performance and under operating conditions potentially different from each other group of photovoltaic cells.

1 . A method for operating a photovoltaic cell array having a plurality of photovoltaic cells, comprising
 collecting the power generated by each group of at least one but less than all of the cells of the array using a plurality of controllers one controller for each group;   converting the power collected at each controller to have a common output parameter, the common output parameter value being greater than the value of the same parameter for each of the individual cells; and   combining the outputs of the controllers to generate an output power of the array.   
     
     
         2 . The method of  claim 1  further comprising
 connecting a different plurality of physically adjacent cells to each controller, the physical relationship being determined so that each of the cells of each plurality has similar operating characteristics.   
     
     
         3 . The method of  claim 2  further comprising
 connecting each said cells of each plurality of cells in one of a series connection, a parallel connection, or a series/parallel connection.   
     
     
         4 . The method of  claim 2  further comprising
 selecting the photovoltaic cells connected to a controller to be physically adjacent to each other and thereby forming a one dimensional, or a two dimensional geographical physical configuration.   
     
     
         5 . The method of  claim 1  further comprising
 connecting said controllers to photovoltaic cells across individual modules, each module having a plurality of photovoltaic cells.   
     
     
         6 . A photovoltaic cell array power control system comprising
 a module having a plurality of photovoltaic cells arranged in a physically adjacent array of cells; and   a plurality of controllers, each controller being connected to a different group of electrically connected photovoltaic cells at their inputs and being interconnected with each other at their outputs, the number of controllers being greater than one;   whereby each group of photovoltaic cells associated with a controller operates at an operating point set solely for the photovoltaic cells of the group connected to the associated controller.   
     
     
         7 . The photovoltaic power system of  claim 6  wherein each group has one photovoltaic cell. 
     
     
         8 . The photovoltaic power system of  claim 6  wherein the number of controllers is less than the number of photovoltaic cells, and each group has at least two photovoltaic cells. 
     
     
         9 . The photovoltaic power system of  claim 8  wherein
 the photovoltaic cells of a group are connected to a controller in one of a parallel connection, a series connection, or a series/parallel connection.   
     
     
         10 . The photovoltaic power system of  claim 8  further wherein
 the photovoltaic cells are arranged in a one dimensional and/or a two dimensional sub-array.